Perhaps the best way to explain the type of racket Manchester City can expect under the floodlights in Naples is to examine why their opponents can no longer shoehorn upwards of 70,000 spectators into the stadium where they like to boast they create the most raucous din in the whole of Italy.

The Stadio San Paolo – a shrieking, fire‑cracking, graffiti‑covered kaleidoscope of colour – may not have a roof and there may be an athletics track separating the pitch from the ultra curves but the noise was still loud enough for the nearest high-rise apartment blocks to start swaying a few years ago.

Large cracks had appeared on the walls before the Neapolitan authorities ruled that the number of fans jumping up and down had left the flats rocking to the point they were in danger of collapsing. Napoli were ordered to reduce their capacity by 1,000 supporters every match until tests showed it was safe. All of which explains why the backdrop to the tie that will go a long way to determining whether City reach the Champions League knockout stages will include a banner in Curva B that reads: "Sito Detesserato". Danger Site.

The restrictions mean there will be just below 60,000 inside the now antiquated stadium that will probably always be associated with the way Diego Maradona used to stick out that chest and tease, bewitch and mesmerise a succession of opponents.

Mancini has mentioned the "incredible atmosphere" just about every time he has been asked about this tie. But football is still waiting for the day when someone leaps from the crowd to score a goal, and the visiting manager was entitled to make his case that City have been sufficiently hardened up under his watch not to be affected by stagefright.

They arrived in Italy after becoming the first club to win 11 of their first 12 matches in the Premier League era. They have accumulated 42 league goals, when last season it took until 5 February to reach that total. They are also the first team to score twice or more in 14 consecutive top-flight matches since Manchester United in 1959. They are, in short, playing with a fearlessness that emboldened Mancini to remark, before the 3-1 defeat of Newcastle United on Saturday that his team were now at the same level as Barcelona and Real Madrid.

The City manager, addressing a predominantly Italian audience in the bowels of the San Paolo, had moderated that boast a little here. "The problem we have is that we have been building these things for only one and a half years," he said. "We've probably built everything too quickly. We still need to improve and for now we are closer to Napoli than we are Real Madrid or Barcelona."

Nonetheless there was a clear confidence in everything he said. "We've got the guys already," he said, when asked whether his team needed a genuine Messi‑level superstar. "We have Balotelli, Agüero, Dzeko, Nasri, Silva … I just think it's too early in terms of our development."

Napoli have not lost any of their past 10 European ties, dating back 17 years, which reflects how this has the potential to be one of City's more difficult assignments since Mancini took over almost two years ago.

On the flipside Walter Mazzarri's team have won only two of their past eight Serie A games. Mancini was asked whether his team would go for broke and replied: "Yes, it is important to have this mentality. We want to go there and play our football and show that Manchester City can be a very good football team."

They have demonstrated that virtually all season but Mancini had been similarly confident before they played against Bayern Munich at the Allianz Arena in September. "We will win in Germany," he had said after the preceding 1-1 home draw against Napoli with which they took their first tentative steps into the competition. Instead they lost 2-0 and Carlos Tevez set in place the mutiny that has left him awol somewhere in Argentina.

Bayern will be City's final opponents and, even if the Bundesliga side have already qualified, Mancini made a point of saying that the Premier League leaders should not expect any favours. Napoli will play Villarreal, who have not picked up a single point in their four games. So it is understandable that he does not want to go to the final game with qualification still undecided. "This is the hardest of all the qualifying groups," he said. "It is not easy. But if we lose, our season is not finished."

Yet a club of City's ambitions do not want to be grubbing around in the Europa League. "We want to win in Naples for this reason," Mancini said. "We want to play in the Champions League but it could be that Bayern will want to knock us out." First, though, City may have to turn down the volume in Naples.